The present invention relates to an optical disk, and a recording/reproducing apparatus and a recording method, for the optical disk, in particular, relates to a circular optical disk in which record signals such as images or voices are ciphered and recorded in order to protect literary properties from illegal copies thereof, and to an apparatus for and a method of reproducing and/or recording the record signals from/to the optical disk.
In general, in a DVD (Digital Versatile Disk) on the market, in which a movie, music or the like is collected (recorded), data information such as an image, voice or the like is ciphered and recorded in order to protect literary properties from illegal copies thereof, namely in order to protect the copyright thereof. Thus, when the DVD is reproduced using a DVD reproducing apparatus, the DVD reproducing apparatus reproduces it by reading key information recorded in a control data area of the DVD, and deciphering the ciphered data information using the key information to reconstruct the original image, voice or the like.
Hereinafter, a conventional DVD and a DVD reproducing apparatus of the above-mentioned type will be concretely described. Hereupon, a DVR-R (i.e. write-once DVD), which is an example of the DVD, will be described.
FIG. 4 is a perspective view showing a rough construction of a conventional DVR-R. In FIG. 4, 101 denotes a DVD-R. 102 denotes a main information area of the DVD-R 101. Data information such as an image, voice or the like is generally ciphered and recorded in the main information area 102. 103 denotes a control data area. The control data area 103 records disk production information and physical format information including key information for deciphering the data information recorded in the main information area 102. Hereupon, the control data area 103 is located at a position of the inner periphery side in the DVD-R 101. In the DVD-R 101, a spiral groove with a wobble is formed from the inner periphery side to the outer periphery side over the both areas 102,103. Thus, the data information is recorded in the recording layer of the groove. Hereupon, the address information, the disk recording condition or the like has been previously recorded on the substrate in the form of an inter-groove pre-pit.
FIG. 5 is a block diagram showing a rough construction of a conventional DVD reproducing apparatus. In FIG. 5, 101 denotes the DVD 101. The DVD 101 records the data information such as an image or voice to be reproduced. 104 denotes an optical pickup. The optical pickup 104 reads record signals of the DVD 101 using laser rays. 105 moves the optical pickup 104 in the radial direction of the DVD 101 in order to read the record signals at arbitrary positions on the DVD 101. 106 denotes a disk motor. The disk motor 106 rotates the DVD 101.
107 denotes a first control circuit. The first control circuit 107 controls the optical pickup 104, the transfer controller 105 and the disk motor 106. 108 denotes an amplifier. The amplifier 108 amplifies the signals, which have been read by the optical pickup 104. 109 denotes a second control circuit. The output signals of the amplifier 108 are inputted into the second control circuit 109. Based on the signals, the second control circuit 109 generates servo signals such as focus error signals, tracking error signals or the like, which are required when the optical pickup 104 reads the record signals of the DVD 101, and then outputs them to the first control circuit 107. Meanwhile, the second control circuit 109 digitizes (makes binary) the input signals of analog type.
110 denotes a demodulation circuit. The demodulation circuit 110 analyzes the signals, which have been read from the DVD 101 to be digitized, while it reconstructs the data information such as the original image or music. 111 denotes a system control circuit. The system control circuit 111 wholly controls the DVD reproducing apparatus.
Hereinafter, actions of the DVD reproducing apparatus having the above-mentioned construction will be described. When the DVD 101 on the market is reproduced, at first, the first control circuit 107 drives and controls the transfer controller 105 in accordance with the instruction of the system control circuit 111. As the result, the transfer controller 105 moves the optical pickup 104 to a position of an inner periphery side in the DVD 101. The signals, which have been read by the optical pickup 104, are amplified by the amplifier 108, and then digitized by the second control circuit 109. The demodulation circuit 110 reads the contents of the digital signals, and then sends the results to the system control circuit 111. If the read contents do not include the key information in the control data area 103 (see FIG. 4), the system control circuit 111 outputs another instruction to the first control circuit 107 again, and then causes the first control circuit 107 to drive and control the transfer controller 105. As the result, the transfer controller 105 moves the optical pickup 104 to a further inner position of the inner periphery side in the DVD 101, and then searches the key information of the DVD 101.
The key information, which has been recorded in the control data area 103 located at a position of the inner periphery side in the DVD 101, is found out by repeating the above-mentioned actions. Then the demodulation circuit 110 reads the key information. If the system control circuit 111 detects that the demodulation circuit 110 has read the key information of the DVD 101, the first control circuit 107 drives and controls the transfer controller 105 in accordance with the instruction of the system control circuit 111. As the result, the transfer controller 105 moves the optical pickup 104 to a position of the outer periphery side in the DVD 101. Then the optical pickup 104 reads the data information recorded in the main information area 102 of the DVD 101 (see FIG. 4). Because the data information is generally ciphered, normal image or voice signals cannot be obtained if the data information is simply reproduced. However, the data information can be deciphered if the key information, which was recorded in the control data region 103 and has been previously read, is used. Thus, the demodulation circuit 110 deciphers the data information in the main information area 102 using the key information, which has been read, so as to reconstruct the original and normal image data or voice data.
However, in the writable optical disk such as a DVD-R or the like, there may be such a problem that a copy of the optical disk may be easily produced by copying the information in the control data area as well as the data information into the DVD-R, even if the data information is ciphered as described above. Thus, in order to physically prevent the information in the control data area from being copied as described above, there has been proposed such a procedure as to previously record other signals at least into the region, in which the key information of the DVD-R is to be recorded, so as to prevent the key information from being copied into the region. That is such a procedure as to prevent the normal key information from being reproduced by the reproducing apparatus by previously forming pre-pits with other information, for example by forming embossment in the control data area including the region in which the key information of the DVD-R is to be recorded, so as to destroy the normal key information.
However, in the conventional optical disk and the reproducing or recording system thereof as described above, it is impossible to record the physical format information and disk production information such as last address information etc. of the writing region, into which data must be written later, into the control data area 103, when the data is recorded into the main information area 102. Thus, if the DVD-R 1 (optical disk), in which the above-mentioned physical format information and disk production information are not recorded into the control data area 103, is reproduced by the DVD-ROM reproducing apparatus, there may occur such a problem that various useful functions, for example the function for detecting the disk volume in a short time to indicate it, are spoiled. Further, there may occur also such a problem that the responsibility associated with the recorded positioning information is deteriorated. In addition, if embossment having stronger restraint for the illegal use is previously formed in the region including the key information of the control data area 103 as the recording pit, it may be extremely difficult to form a wobble in the region. In consequence, if the DVD is reproduced using the DVD reproducing apparatus, there occurs such a problem that it may be accidentally judged that the DVD is a DVD-ROM though it is practically a DVD-R, because no wobble exists in the region.
The present invention is achieved to solve the conventional problems described above. Thus, it has an object to provide an optical disk and an apparatus for and method of recording or reproducing the optical disk, which can precisely identify the type of the optical disk and can effectively prevent the illegal use of the optical disk such as a DVD or the like, which infringes the copyright, without spoiling the functions for recording or reproducing the physical format information, the disk production information (disk control information) and so on.
An optical disk according to the first aspect of the present invention which has been achieved to solve the above-mentioned problems, including (i) a main information area in which ciphered data information can be recorded in a recording layer of a groove having a wobble in such a manner that the data information can be read using light, (ii) a first control data area located at an inner periphery side in comparison with the main information area, and (iii) a second control data area located at an inner periphery side in comparison with the main information area, the second control data area being able to record information with an information structure which is different from an information structure of the first control data area, is characterized in that (iv) the first control data area is provided with a region which can record disk production information and physical format information including key information for deciphering the data information, other information having been previously recorded in another region, which can record at least the key information, in the first control data area, and (v) the second control data area being able to record the disk production information and the physical format information which does not include the key information.
Further, another optical disk according to the second aspect of the present invention, including (i) a main information area in which ciphered data information can be recorded in a recording layer of a groove having a wobble in such a manner that the data information can be read using light, (ii) a first control data area located at an inner periphery side in comparison with the main information area, and (iii) a second control data area located at an inner periphery side in comparison with the main information area, the second control data area being able to record information with a physical structure which is different from a physical structure of the first control data area, is characterized in that (iv) the second control data area can record disk production information and physical format information which does not include key information for deciphering the data information.
In the optical disk according to the second aspect of the present invention, it is preferable that the physical structure is composed of a wobble, the first control data area being provided with no wobble, and the second control data area being provided with the wobble.
In the optical disk according to the first or second aspect of the present invention, a pit, which has recorded information including an address signal, may be provided at an inter-groove position in the second control data area.
Meanwhile, in the optical disk according to the first or second aspect of the present invention, a recording pit in the first control data area may be composed of embossment, while a recording pit in the second control data area may be formed by a laser light.
Hereupon, as an example of the optical disk according to the first or second aspect of the present invention, for example, a write-once optical disk is pointed out.
A recording/reproducing apparatus for an optical disk according to the third aspect of the present invention, including (i) a main information area in which ciphered data information can be recorded in a recording layer of a groove having a wobble, (ii) a first control data area which can record disk production information and physical format information including key information for deciphering the data information, and (iii) a second control data area, (iv) the apparatus being able to record and/or reproduce the data information, is characterized in the (v) the recording/reproducing apparatus can record or reproduce the disk production information and the physical format information without the key information into the second control data area, with a structure which is different from a structure of the first control data area, when the optical disk is recorded or reproduced, respectively.
Another recording/reproducing apparatus for an optical disk according to the fourth aspect of the present invention, including (i) a main information area in which ciphered data information can be recorded in a recording layer of a groove having a wobble, (ii) a first control data area which can record disk production information and physical format information including key information for deciphering the data information, and (iii) a second control data area, in which (iv) a structure of the first control data area and a structure of the second control data area are different from each other, the apparatus being able to record and/or reproduce the data information, is characterized in that (v) the recording/reproducing apparatus can record or read the disk production information and the physical format information without the key information using the second control data area, when the optical disk is recorded or reproduced, respectively.
In the recording/reproducing apparatus for the optical disk according to the third or fourth aspect of the present invention, the optical disk may be an optical disk in which information has been previously recorded at least in a portion of the first control data area.
Hereupon, as an example of the optical disk which is used in the recording/reproducing apparatus for the optical disk according to the third or fourth aspect of the present invention, for example, a write-once optical disk is pointed out.
A recording method for an optical disk according to the fifth aspect of the present invention, including (i) a main information area in which ciphered data information can be recorded in a recording layer of a groove having a wobble, (ii) a first control data area which can record disk production information and physical format information including key information for deciphering the data information, and (iii) a second control data area, the method being for recording the data information, is characterized in that the method includes the steps of (iv) detecting whether a loaded optical disk is writable or not, and (v) writing the disk production information and the physical format information without the key information into the second control data area, if the optical disk is writable.
In the recording method for the optical disk, it may be detected whether the loaded optical disk is writable or not, on the basis of whether a wobble exists or not.
In the optical disk, the recording/reproducing apparatus for recording and/or reproducing the optical disk or the recording method for the optical disk, according to the present invention, the disk can be precisely identified without spoiling the physical format information, the disk production information (disk control information) or the like. In addition, illegal use of a DVD or another optical disk leading up to breach of the copyright may be effectively prevented. Further, it may become possible to previously form a recording pit composed of embossment, which has stronger restraint for preventing the illegal use and can be formed with a lower cost. In consequence, the optical disk may be manufactured with a lower cost.